Display device

ABSTRACT

Disclosed is a display device capable of reducing the thickness and the weigh thereof. In an organic light-emitting diode display device having a touch sensor, a plurality of routing lines, which are connected respectively to a plurality of touch sensors disposed on an encapsulation unit, are disposed on different planes so as to overlap each other and are electrically connected to each other through a plurality of routing contact holes. Thereby, a connection fault between the routing lines is prevented. In addition, through the provision of the touch sensors above the encapsulation unit, a separate attachment process is unnecessary, which results in a simplified manufacturing process and reduced costs.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2017-0057291, filed on May 8, 2017, which is hereby incorporated byreference in its entirety as if fully set forth herein.

BACKGROUND Field of the Disclosure

The present disclosure relates to a display device, and moreparticularly, to a display device and a method of manufacturing the samefor achieving a simplified manufacturing process and reduced costs.

Description of the Background

A touchscreen is an input device that allows a user to input a commandby selecting a content appearing on a screen of a display device or thelike with the human hand or an object. That is, the touchscreen convertsa contact position that the human hand or the object directly touchesinto an electrical signal, and receives the content selected at thecontact position as an input signal. The touchscreen may eliminate aseparate input device, which is connected to the display device andoperates, such as a keyboard or a mouse, and thus the use range thereofis gradually expanding.

Such a touchscreen is generally attached to the front surface of adisplay panel, such as a liquid crystal display panel or an organiclight-emitting diode display panel, via an adhesive. In this case, sincethe touchscreen is separately manufactured and attached to the frontsurface of the display panel, the manufacturing process becomescomplicated and the costs can be increased due to the addition of suchan attachment process.

SUMMARY

Accordingly, the present disclosure is directed to a display device thatsubstantially obviates one or more problems due to limitations anddisadvantages of the related art.

The present disclosure has been provided to solve the problems describedabove, and the present disclosure is to provide a display device and amethod of manufacturing the same for achieving a simplifiedmanufacturing process and reduced costs.

Additional advantages and features of the disclosure will be set forthin part in the description which follows and in part will becomeapparent to those having ordinary skill in the art upon examination ofthe following or may be learned from practice of the disclosure. Theother advantages of the disclosure may be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the disclosure, as embodied and broadly described herein, an organiclight-emitting diode display device having a touch sensor is configuredsuch that a plurality of routing lines, which are connected respectivelyto a plurality of touch sensors above an encapsulation unit, aredisposed on different planes so as to overlap each other and areelectrically connected to each other through a plurality of routingcontact holes, whereby a connection fault between the routing lines isprevented. In addition, through the provision of the touch sensors abovethe encapsulation unit, a separate attachment process is unnecessary,which results in a simplified manufacturing process and reduced costs.

In another aspect of the present disclosure, a display device includinga light-emitting element disposed on a substrate; an encapsulation unitdisposed on the light-emitting element; a plurality of touch sensorsdisposed over the encapsulation unit; a touch insulation layer disposedon the encapsulation unit; a lower routing line disposed on the touchinsulation layer having a plurality of routing contact holes andcovering a lateral surface of the encapsulation unit; and an upperrouting line disposed on the touch insulation layer along the lowerrouting line and connected to the lower routing line through theplurality of routing contact holes, wherein the lower routing line andthe upper routing line are disposed on different planes and overlap eachother.

In a further aspect of the present disclosure, A method of manufacturinga display device including forming a light-emitting element on asubstrate; forming an encapsulation unit on the light-emitting element;forming a plurality of touch sensors above the encapsulation unit; andforming a plurality of routing lines connected to the plurality of touchsensors and covering a side surface of the encapsulation unit, whereinthe plurality of routing lines are disposed on different planes tooverlap each other and is electrically connected to each other through aplurality of routing contact holes.

It is to be understood that both the foregoing general description andthe following detailed description of the present disclosure areexemplary and explanatory and are intended to provide furtherexplanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate aspect(s) of the disclosure andtogether with the description serve to explain the principle of thedisclosure.

In the drawings:

FIG. 1 is a perspective view illustrating an organic light-emittingdiode display device having a touch sensor according to the presentdisclosure;

FIG. 2 is a plan view illustrating the organic light-emitting diodedisplay device having the touch sensor illustrated in FIG. 1;

FIG. 3 is a cross-sectional view illustrating the organic light-emittingdiode display device having the touch sensor taken along lines “I-I” and“II-II” of FIG. 2;

FIGS. 4A and 4B are a plan view and a cross-sectional view respectivelyfor explaining a method of manufacturing a second bridge, a lowerrouting line, and a lower pad electrode illustrated in FIGS. 2 and 3;

FIGS. 5A and 5B are a plan view and a cross-sectional view forexplaining a method of manufacturing a touch contact hole, a routingcontact hole, and a pad contact hole illustrated in FIGS. 2 and 3;

FIGS. 6A and 6B are a plan view and a cross-sectional view forexplaining a method of manufacturing first and second touch electrodes,a first bridge, an upper routing line, and an upper pad electrodeillustrated in FIGS. 2 and 3;

FIGS. 7A to 7D are cross-sectional views for explaining the method ofmanufacturing the first and second touch electrodes, the first bridge,the upper routing line, and the upper pad electrode illustrated in FIG.6B in detail;

FIGS. 8A and 8B are a plan view and a cross-sectional view forexplaining a method of manufacturing a touch protective layerillustrated in FIGS. 2 and 3;

FIG. 9 is a cross-sectional view illustrating an organic light-emittingdiode display device having a touch sensor according to another aspectof the present disclosure; and

FIG. 10 is a plan view and a cross-sectional view illustrating anotherform of the bridges in the organic light-emitting diode display devicehaving a touch sensor according to the present disclosure.

DETAILED DESCRIPTION

Hereinafter, aspects according to the present disclosure will bedescribed in detail with reference to the accompanying drawings.Whenever possible, the same reference numbers will be used throughoutthe drawings to refer to the same or like parts.

FIG. 1 is a perspective view illustrating an organic light-emittingdiode display device having a touch sensor according to the presentdisclosure.

The organic light-emitting diode display device having a touch sensorillustrated in FIG. 1 senses the presence or absence of a touch and atouch position by sensing a variation in mutual capacitance Cm (touchsensor) in response to a user touch via touch electrodes 152 e and 154 eillustrated in FIG. 2 during a touch period. Then, the organiclight-emitting diode display device having a touch sensor illustrated inFIG. 1 displays an image via unit pixels each including a light-emittingelement 120. Each unit pixel may include red (R), green (G), and blue(B) subpixels PXL, or may include red (R), green (G), blue (B), andwhite (W) subpixels PXL.

To this end, the organic light-emitting diode display device illustratedin FIG. 1 includes a plurality of subpixels PXL arranged in a matrixform on a substrate 111, an encapsulation unit 140 disposed on thesubpixels PXL, and a mutual capacitance array Cm disposed on theencapsulation unit 140.

Each of the subpixels PXL includes a pixel drive circuit and thelight-emitting element 120 connected to the pixel drive circuit.

The pixel drive circuit includes a switching transistor T1, a drivingtransistor T2, and a storage capacitor Cst.

The switching transistor T1 is turned on when a scan pulse is suppliedto a scan line SL, and supplies a data signal supplied to a data line DLto the storage capacitor Cst and a gate electrode of the drivingtransistor T2.

The driving transistor T2 controls current to be supplied from ahigh-voltage (VDD) supply line to the light-emitting element 120 inresponse to the data signal supplied to the gate electrode of thedriving transistor T2, thereby adjusting the amount of emission of lightfrom the light-emitting element 120. Then, even if the switchingtransistor T1 is turned off, the driving transistor T2 maintains theemission of light of the light-emitting element 120 by supplying aconstant amount of current thereto by a voltage charged in the storagecapacitor Cst until a data signal of a next frame is supplied.

The driving transistor T2 or 130, as illustrated in FIG. 3, includes agate electrode 132, a semiconductor layer 134 overlapping the gateelectrode 132 with a gate insulation layer 102 therebetween, and sourceand drain electrodes 136 and 138 formed on an interlayer insulationlayer 114 to come into contact with the semiconductor layer 134. Here,the semiconductor layer 134 is formed on a buffer layer 104 using atleast one of an amorphous semiconductor material, a polycrystallinesemiconductor material, and an oxide semiconductor material.

The light-emitting element 120 includes an anode electrode 122, at leastone light-emitting stack 124 formed on the anode electrode 122, and acathode electrode 126 formed on the light-emitting stack 124.

The anode electrode 122 is electrically connected to the drain electrode138 of the driving transistor T2 or 130, which is exposed through apixel contact hole formed in a protective layer 116.

The light-emitting stack 124 is formed on the anode electrode 122 in alight-emitting area that is defined by a bank 128. The light-emittingstack 124 is formed by stacking a hole-related layer, an organicemission layer, and an electron-related layer on the anode electrode 122in this order or in the reverse order. In addition, the at least onelight-emitting stack 124 may include first and second light-emittingstacks, which face each other with a charge generation layertherebetween. In this case, the organic emission layer of any one of thefirst and second light-emitting stacks generates blue light, and theorganic emission layer of the other one of the first and secondlight-emitting stacks generates yellow-green light, whereby white lightis generated via the first and second light-emitting stacks. Since thewhite light generated in the light-emitting stack 124 is incident on acolor filter located above or below the light-emitting stack 124, acolor image may be realized. In addition, colored light corresponding toeach subpixel may be generated in each light-emitting stack 124 torealize a color image, without a separate color filter. That is, thelight-emitting stack 124 of the red (R) subpixel may generate red light,the light-emitting stack 124 of the green (G) subpixel may generategreen light, and the light-emitting stack 124 of the blue (B) subpixelmay generate blue light.

The cathode electrode 126 may be formed so as to face the anodeelectrode 122 with the light-emitting stack 124 therebetween, and isconnected to a low-voltage (VSS) supply line.

The encapsulation unit 140 prevents external moisture or oxygen fromentering the light-emitting element 120, which is vulnerable to theexternal moisture or oxygen. To this end, the encapsulation unit 140includes a plurality of inorganic encapsulation layers 142 and 146 andan organic encapsulation layer 144 disposed between the inorganicencapsulation layers 142 and 146. The inorganic encapsulation layer 146is the uppermost layer. Here, the encapsulation unit 140 includes atleast two inorganic encapsulation layers 142 and 146 and at least oneorganic encapsulation layer 144. In the present disclosure, thestructure of the encapsulation unit 140 in which the organicencapsulation layer 144 is disposed between the first and secondinorganic encapsulation layers 142 and 146 will be described by way ofexample.

The first inorganic encapsulation layer 142 is formed on the substrate111, on which the cathode electrode 126 has been formed, so as to beclosest to the light-emitting element 120. The first inorganicencapsulation layer 142 is formed of an inorganic insulation materialthat is capable of being deposited at a low temperature, such as siliconnitride (SiN_(x)), silicon oxide (SiO_(x)), silicon oxide nitride(SiON), and aluminum oxide (Al₂O₃). Thus, since the first inorganicencapsulation layer 142 is deposited under a low-temperature atmosphere,it is possible to prevent damage to the light-emitting stack 124, whichis vulnerable to a high-temperature atmosphere, during the depositionprocess of the first inorganic encapsulation layer 142.

The organic encapsulation layer 144 serves to dampen the stress betweenthe respective layers caused by bending the organic light-emitting diodedisplay device and to increase planarization performance. The organicencapsulation layer 144 is formed using an organic insulation material,such as an acryl resin, epoxy resin, polyimide, polyethylene, andsilicon oxycarbide (SiOC).

The second inorganic encapsulation layer 146 is formed so as to coverthe upper surface and the side surface of the organic encapsulationlayer 144 and the upper surface of the first inorganic encapsulationlayer 142 that is exposed by the organic encapsulation layer 144. Thus,since the upper and lower surfaces of the organic encapsulation layer144 are sealed by the first and second inorganic encapsulation layers142 and 146, it is possible to minimize or prevent external moisture oroxygen from entering the organic encapsulation layer 144, or to minimizeor prevent moisture or oxygen in the organic encapsulation layer 144from entering the light-emitting element 120. The second inorganicencapsulation layer 146 is formed of an inorganic insulation material,such as silicon nitride (SiN_(x)), silicon oxide (SiO_(x)), siliconoxide nitride (SiON), and aluminum oxide (Al₂O₃).

On the encapsulation unit 140, a touch sensing line 154 and a touchdriving line 152 are disposed so as to intersect each other with a touchinsulation layer 156 therebetween. The mutual capacitance array Cm isformed at the intersection of the touch sensing line 154 and the touchdriving line 152. Thus, the mutual capacitance array Cm serves as atouch sensor by storing charges in response to a touch driving pulsesupplied to the touch driving line 152 and discharging the stored chargeto the touch sensing line 154.

The touch driving line 152 includes a plurality of first touchelectrodes 152 e, and first bridges 152 b, which electricallyinterconnect the first touch electrodes 152 e.

The first touch electrodes 152 e are equidistantly spaced apart fromeach other in the Y-direction, which is a first direction, on the touchinsulation layer 156. Each of the first touch electrodes 152 e iselectrically connected to an adjacent first touch electrode 152 e viathe first bridge 152 b.

The first bridge 152 b is disposed on the touch insulation layer 156 inthe same plane as the first touch electrode 152 e, and is electricallyconnected to the first touch electrode 152 e without a separate contacthole.

The touch sensing line 154 includes a plurality of second touchelectrodes 154 e, and second bridges 154 b, which electricallyinterconnect the second touch electrodes 154 e.

The second touch electrodes 154 e are equidistantly spaced apart fromeach other in the X-direction, which is a second direction, on the touchinsulation layer 156. Each of the second touch electrodes 154 e iselectrically connected to an adjacent second touch electrode 154 e viathe second bridge 154 b.

The second bridge 154 b is formed on the second inorganic encapsulationlayer 146 and is exposed through a touch contact hole 150, which isformed in the touch insulation layer 156, so as to be electricallyconnected to the second touch electrode 154 e. The second bridge 154 bis disposed so as to overlap the bank 128, in the same manner as thefirst bridge 152 b, which may prevent damage to the aperture ratio dueto the first and second bridges 152 b and 154 b.

In this way, the touch driving line 152 and the touch sensing line 154of the present disclosure are connected respectively to a touch driveunit (not illustrated) via a routing line 160 and a touch pad 170, whichare disposed in a non-active (bezel) area.

As such, the routing line 160 transmits a touch driving pulse generatedin the touch drive unit to the touch driving line 152 via the touch pad170, and also transmits a touch signal from the touch sensing line 154to the touch pad 170.

The routing line 160 is disposed between each of the first and secondtouch electrodes 152 e and 154 e and the touch pad 170 to electricallyinterconnect these 152 e, 154 e and 170. The routing line 160 connectedto the first touch electrode 152 e, as illustrated in FIG. 2, extends toat least one of the upper side and the lower side of an active area soas to be connected to the touch pad 170. The routing line 160 connectedto the second touch electrode 154 e extends to at least one of the rightside and the left side of the active area so as to be connected to thetouch pad 170. The arrangement of the routing line 160 is not limited tothe structure of FIG. 2, and may be changed in various ways according todesign requirements of the display device.

A plurality of routing lines 160 is provided on different planes so asto overlap each other. In the present disclosure, the structure in whichthe routing lines 160 include lower and upper routing lines 162 and 164disposed on different planes will be described by way of example.

The lower routing line 162 is formed by the same mask process as thesecond bridge 154 b using the same material as the second bridge 154 b.The lower routing line 162 is formed on the second inorganicencapsulation layer 146, which is the uppermost layer of theencapsulation unit 140, so as to cover the side surface of theencapsulation unit 140. Since the lower routing line 162 is protected bythe touch insulation layer 156, it is possible to prevent damage to thelower routing line 162 when patterning the upper routing line 164, whichresults in increased reliability.

The upper routing line 164 is formed by the same mask process as thetouch electrodes 152 e and 154 e using the same material as the touchelectrodes 152 e and 154 e. The upper routing line 164 is disposed onthe touch insulation layer 156, which is formed so as to cover the lowerrouting line 162, and is also formed to cover the side surface of thetouch insulation layer 156. In addition, the upper routing line 164 isformed on the touch insulation layer 156 so as to extend along the lowerrouting line 162 and to have the same shape as the lower routing line162. The upper routing line 164 extends from each of the first andsecond touch electrodes 152 e and 154 e, and overlaps the lower routingline 162 with the touch insulation layer 156 therebetween.

The upper routing line 164 is electrically connected to the lowerrouting line 162, which is exposed through a plurality of routingcontact holes 166 formed in the touch insulation layer 156. The routingcontact holes 166 may serve to increase connection areas between theupper routing line 164 and the lower routing line 162, and thus mayprevent a connection fault between the upper routing line 164 and thelower routing line 162. In addition, since the routing line 160, whichincludes the upper routing line 164 and the lower routing line 162, isformed to have a multilayered structure, it is possible to reduce theresistance of the routing line 160. Moreover, since the routing line 160has a multilayered structure, even if any one of the upper and lowerrouting lines 162 and 164 is disconnected, the other routing line mayperform transmission of the touch driving pulse and the touch signal.

The touch pad 170 is formed so as to be exposed outwards by a touchprotective layer 190, and thus is connected to a signal transmissionfilm on which the touch drive unit (not illustrated) is mounted. Thetouch pad 170 may be disposed in at least one of one side area and theother side area of the substrate 111, together with a display pad (notillustrated) connected to at least one of the data line DL, the scanline SL, the low-voltage (VSS) supply line, and the high-voltage (VDD)supply line. Alternatively, the touch pad 170 and the display pad may bedisposed in different non-active areas. Meanwhile, the arrangement ofthe touch pad 170 is not limited to the structure of FIG. 2, and may bechanged in various ways according to necessary design requirements ofthe display device.

The touch pad 170 is disposed on at least one layer 116 among aplurality of insulation layers 102, 104, 114, 116 and 118 disposed belowthe light-emitting element 120. The touch pad 170 includes a lower padelectrode 172 extending from the lower routing line 162 and an upper padelectrode 174 extending from the upper routing line 164.

The lower pad electrode 172 is formed by the same mask process as thesecond bridge 154 b using the same material as the second bridge 154 b.The lower pad electrode 172 extends from the lower routing line 162 onthe protective layer 116, and thus, is directly connected to the lowerrouting line 162.

The upper pad electrode 174 is formed by the same mask process as thetouch electrodes 152 e and 154 e using the same material as the touchelectrodes 152 e and 154 e. The upper pad electrode 174 is electricallyconnected to the lower pad electrode 172, which is exposed through a padcontact hole 176 formed in the touch insulation layer 156.

In this way, in the present disclosure, each of the first and secondtouch electrodes 152 e and 154 e, the first and second bridge 152 b and154 b, the upper routing line 164, and the upper pad electrode 174 isformed of the transparent conductive layer 161 and the opaque conductivelayer 163 disposed on or beneath the transparent conductive layer 161.The transparent conductive layer 161 is formed in a single layer or inmultiple layers using at least one of ITO, IZO, ZnO, IGZO, andITO/Ag/ITO. The opaque conductive layer 163 is formed in a single layeror in multiple layers using a highly conductive material having strongcorrosion resistance and acid resistance, such as Al, Ti, Cu, and Mo.For example, the opaque conductive layer 163 is formed in atriple-layered structure as a stack of Ti/Al/Ti or Mo/Al/Mo.

The transparent and opaque conductive layers 161 and 163 of each of theupper routing line 164 and the upper pad electrode 174 are formed tohave the same shape. That is, the opaque conductive layer 163 of each ofthe upper routing line 164 and the upper pad electrode 174 is formed onthe transparent conductive layer 161 of each of the upper routing line164 and the upper pad electrode 174 so as to have the same shape and thesame line width as those of the transparent conductive layer 161.

The opaque conductive layer 163 of each of the first and second touchelectrodes 152 e and 154 e and the first and second bridges 152 b and154 b is formed to have a line width smaller than that of thetransparent conductive layer 161 of each of the first and second touchelectrodes 152 e and 154 e and the first and second bridges 152 b and154 b. That is, the opaque conductive layer 163 of each of the first andsecond touch electrodes 152 e and 154 e and the first and second bridges152 b and 154 b is formed on the transparent conductive layer 161 tohave a mesh shape. The opaque conductive layer 163 has conductivityhigher than that of the transparent conductive layer 161, so that thefirst and second touch electrodes 152 e and 154 e may be formed aslow-resistance electrodes. Thereby, the resistance and the capacitanceof the first and second touch electrodes 152 e and 154 e may be reduced,which may result in a reduced RC time constant and increased touchsensitivity. In addition, since the mesh-shaped opaque conductive layer163 has a very small line width, it is possible to prevent deteriorationin the aperture ratio and transmissivity due to the mesh-shaped opaqueconductive layer 163.

FIGS. 4A to 8B are plan views and cross-sectional views for explaining amethod of manufacturing the organic light-emitting diode display devicehaving the touch sensor illustrated in FIGS. 2 and 3.

Referring to FIGS. 4A and 4B, the second bridge 154 b, the lower routingline 162, and the lower pad electrode 172 are formed on the substrate111 having the switching transistor T1, the driving transistor T2 or130, the light-emitting element 120, and the encapsulation unit 140formed thereon.

Specifically, a conductive layer is deposited on the entire surface ofthe substrate 111, having the switching transistor T1, the drivingtransistor T2 or 130, the light-emitting element 120, and theencapsulation unit 140 formed thereon, by a deposition process.Subsequently, the conductive layer is patterned by a photolithographyprocess and an etching process using a first mask, whereby the secondbridge 154 b, the lower routing line 162, and the lower pad electrode172 are formed. Here, each of the second bridge 154 b, the lower routingline 162, and the lower pad electrode 172 is formed in a single layer orin multiple layers using a having good conductivity, and strongcorrosion resistance and acid resistance, such as Al, Ag, Ti, Cu, Mo,and MoTi. For example, each of the second bridge 154 b, the lowerrouting line 162, and the lower pad electrode 172 is formed in atriple-layered structure as a stack of Ti/Al/Ti or Mo/Al/Mo.

Referring to FIGS. 5A and 5B, the touch insulation layer 156, whichincludes the touch contact hole 150, the routing contact hole 166, andthe pad contact hole 176, is formed on the substrate 111 having thesecond bridge 154 b, the lower routing line 162, and the lower padelectrode 172 formed thereon.

Specifically, the touch insulation layer 156 is formed by depositing aninorganic or organic insulation material on the substrate 111 having thesecond bridge 154 b, the lower routing line 162, and the lower padelectrode 172 formed thereon. Here, the touch insulation layer 156 maybe an inorganic layer such as SiN_(x), SiON, and SiO₂, or may be anacryl-based, epoxy-based, Parylene-C, Parylene-N, Parylene-F, orsiloxane-based organic layer. Subsequently, the touch insulation layer156 is patterned by a photolithography process and an etching processusing a second mask, whereby the touch contact hole 150, the routingcontact hole 166, and the pad contact hole 176 are formed.

Referring to FIGS. 6A and 6B, the first and second touch electrodes 152e and 154 e, the first bridge 152 b, the upper routing line 164, and theupper pad electrode 174 are formed on the substrate 111 having the touchcontact hole 150, the routing contact hole 166, and the pad contact hole176 formed thereon. This will be described below with reference to FIGS.7A to 7D.

As illustrated in FIG. 7A, the transparent conductive layer 161 and theopaque conductive layer 163 are sequentially laminated on the substrate111 having the touch contact hole 150, the routing contact hole 166, andthe pad contact hole 176 formed thereon. Here, the transparentconductive layer 161 is formed of a transparent conductive layer, suchas ITO, IZO, ZnO, IGZO, and ITO/Ag/ITO, and the opaque conductive layer163 is formed in a single layer or in multiple layers using a havinggood conductivity, and strong corrosion resistance and acid resistance,such as Al, Ag, Ti, Cu, Mo, and MoTi. For example, the opaque conductivelayer 163 is formed in a triple-layered structure as a stack of Ti/Al/Tior Mo/Al/Mo.

Subsequently, after a photosensitive layer is laminated on the opaqueconductive layer 163, the photosensitive layer is patterned by aphotolithography process using a third mask, such as a half-tone mask ora slit mask, whereby a photosensitive layer 180 having a multilayeredstructure is formed. The multilayered photosensitive layer 180 is formedto have a second thickness d2 in the area in which the mesh-shapedopaque conductive layer 163 of each of the first and second touchelectrodes 152 e and 154 e and the first bridge 152 b, the upper routingline 164, and the upper pad electrode 174 are formed, and is also formedto have a first thickness in the area in which the transparentconductive layer 161 is formed so as to be exposed by the mesh-shapedopaque conductive layer 163 of each of the first and second touchelectrodes 152 e and 154 e and the first bridge 152 b. Thephotosensitive layer 180 is not formed in the remaining area.

The opaque conductive layer 163 and the transparent conductive layer 161are etched through an etching process using the multilayeredphotosensitive layer 180 as a mask. Thereby, as illustrated in FIG. 7B,each of the first and second touch electrodes 152 e and 154 e, the firstbridge 152 b, the upper routing line 164, and the upper pad electrode174 is formed to have a multilayered structure that includes thetransparent and opaque conductive layers 161 and 163 having the sameline width.

Subsequently, by ashing the multilayered photosensitive layer 180, asillustrated in FIG. 7C, the total thickness of the photosensitive layer180 is reduced such that a portion of the photosensitive layer 180,which has the first thickness, is removed, whereby the opaque conductivelayer 163 of each of the first and second touch electrodes 152 e and 154e and the first bridge 152 b is exposed. Subsequently, when the exposedopaque conductive layer 163 is removed through an etching process usingthe multilayered photosensitive layer 180, subjected to ashing, as amask, as illustrated in FIG. 7D, the transparent conductive layer 161 ofeach of the first and second touch electrodes 152 e and 154 e and thefirst bridge 152 b is exposed. Subsequently, the photosensitive layer180 remaining on the substrate is removed through a stripping process,as illustrated in FIG. 6B.

Referring to FIGS. 8A and 8B, the touch protective layer 190 is formedon the substrate 111 having the first and second touch electrodes 152 eand 154 e, the first bridge 152 b, the upper routing line 164, and theupper pad electrode 174 formed thereon.

Specifically, an organic insulation material, such as aphoto-acryl-based resin, is applied to the entire surface of thesubstrate 111 having the first and second touch electrodes 152 e and 154e, the first bridge 152 b, the upper routing line 164, and the upper padelectrode 174 formed thereon. Subsequently, the organic insulationmaterial is patterned by a photolithography process and an etchingprocess using a fourth mask. Thereby, as illustrated in FIG. 8B, thetouch protective layer 190 is formed so as to expose the touch pad 170.

In this way, in the display panel according to the present disclosure,the transparent conductive layer 161 and the mesh-shaped opaqueconductive layer 163, which are included in each of the touch electrodes152 e and 154 e, are formed through the same mask process. Thereby, thepresent disclosure may achieve a simplified process and reduced costsowing to a reduced number of mask processes.

FIG. 9 is a cross-sectional view illustrating an organic light-emittingdiode display device according to another aspect of the presentdisclosure.

The organic light-emitting diode display device illustrated in FIG. 9includes the same constituent elements as those of the organiclight-emitting diode display device illustrated in FIG. 3, except thatit further includes color filters 192 disposed between the encapsulationunit 140 and the touch electrodes 152 e and 154 e. Thus, a detaileddescription related to the same constituent elements will be omittedbelow.

The color filters 192 are formed between each of the touch sensing line154 and the touch driving line 152 and the light-emitting element 120.The distance between each of the touch sensing line 154 and the touchdriving line 152 and the light-emitting element 120 is increased by thecolor filters 192. Thereby, the capacitance of a parasitic capacitorformed between each of the touch sensing line 154 and the touch drivingline 152 and the light-emitting element 120 may be minimized, and mutualinteraction due to coupling between each of the touch sensing line 154and the touch driving line 152 and the light-emitting element 120 may beprevented. In addition, the color filters 192 may prevent a chemicalsolution (e.g., developing solution or etching solution) used in theprocess of manufacturing the touch sensing line 154 and the touchdriving line 152, external moisture, and the like from entering thelight-emitting stack 124. Thereby, the color filters 192 may preventdamage to the light-emitting stack 124, which is vulnerable to thechemical solution or moisture. Meanwhile, as illustrated in FIG. 9, theconfiguration in which the touch electrodes 152 e and 154 e are disposedover the color filters 192 has been described by way of example, but thecolor filters 192 may be disposed over the touch electrodes 152 e and154 e. In this case, the touch electrodes 152 e and 154 e are disposedbetween the color filters 192 and the encapsulation unit 140.

A black matrix 194 is disposed between the color filters 192. The blackmatrix 194 serves to separate the respective subpixel areas from eachother and to prevent optical interference and light leakage betweenadjacent subpixel areas. The black matrix 194 may be formed of ahigh-resistance black insulation material, or may be formed by stackingat least two colors of color filters among red (R), green (G), and blue(B) color filters 192. In addition, a touch planarization layer 196 isformed on the substrate 111 having the color filters 192 and the blackmatrix 194 formed thereon. The substrate 111 having the color filters192 and the black matrix 194 formed thereon is flattened by the touchplanarization layer 196.

Meanwhile, in the present disclosure, the first and second bridges 152 band 154 b may include a plurality of slits 153, as illustrated in FIG.10. The second bridge 154 b having the slits 153, illustrated in FIG.10, may have a reduced surface area, compared to the second bridge 154 bhaving no slit 153 illustrated in FIG. 3. Thereby, the reflection ofexternal light by the second bridge 154 b may be reduced, which mayprevent deterioration in visibility. In addition, in the presentdisclosure, the mutual-capacitance-type touch sensor, which is formedbetween the touch sensing line 154 and the touch driving line 152intersecting each other, has been described by way of example, thepresent disclosure may also be applied to a self-capacitance-type touchsensor Cs.

As is apparent from the above description, in a display device accordingto the present disclosure, a plurality of routing lines, which areconnected respectively to a plurality of touch sensors, are disposed ondifferent planes so as to overlap each other and are electricallyconnected to each other through a plurality of routing contact holes.Thereby, according to the present disclosure, it is possible to preventa connection fault between the routing lines. In addition, in thepresent disclosure, a transparent conductive layer and a mesh-shapedopaque conductive layer, which are included in each touch electrode, areformed through the same mask process. Thereby, it is possible tosimplify a manufacturing process and to reduce costs, through reductionin the number of mask processes. Moreover, a conventional organiclight-emitting diode display device includes a touchscreen attachedthereto using an adhesive, whereas an organic light-emitting diodedisplay device of the present disclosure includes touch electrodesdisposed on an encapsulation unit, which may make a separate attachmentprocess be unnecessary, resulting in a simplified manufacturing processand reduced costs.

Although the aspects of the present disclosure have been described abovein detail with reference to the accompanying drawings, it will beapparent to those skilled in the art that the present disclosuredescribed above is not limited to the aspects described above, andvarious substitutions, modifications, and alterations may be devisedwithin the spirit and scope of the present disclosure.

What is claimed is:
 1. A display device comprising: a light-emittingelement disposed on a substrate; an encapsulation unit disposed on thelight-emitting element; a plurality of touch sensors disposed above theencapsulation unit; and a plurality of routing lines connected to theplurality of touch sensors and covering a side surface of theencapsulation unit, wherein the plurality of routing lines are disposedon different planes so as to overlap each other and are electricallyconnected to each other through a plurality of routing contact holes. 2.The display device according to claim 1, wherein the plurality ofrouting lines comprise: a lower routing line disposed on theencapsulation unit; and an upper routing line connected to the lowerrouting line through the plurality of routing contact holes, which areformed in a touch insulation layer covering the lower routing line, andwherein the upper routing line is disposed on the touch insulation layerand is provided along the lower routing line.
 3. The display deviceaccording to claim 2, wherein the plurality of touch sensors comprise atouch sensing line and a touch driving line disposed on theencapsulation unit so as to intersect each other, wherein the touchdriving line comprises: a plurality of first touch electrodes arrangedin a first direction on the encapsulation unit; and a first bridgeinterconnecting the plurality of first touch electrodes, wherein thetouch sensing line comprises: a plurality of second touch electrodesarranged in a second direction intersecting the first direction; and asecond bridge interconnecting the second touch electrodes, wherein thelower routing line is formed of the same material as one of the firstand second bridges, and wherein the upper routing line extends from eachof the first and second touch electrodes.
 4. The display deviceaccording to claim 3, further comprising a touch pad disposed on atleast one of a plurality of insulation layers, which are disposed underthe light-emitting element, and extended from the plurality of routinglines, wherein the touch pad comprises: a lower pad electrode extendedfrom the lower routing line; and an upper pad electrode extended fromthe upper routing line.
 5. The display device according to claim 4,wherein at least one of the upper routing line, the upper pad electrode,the first bridge, the first touch electrodes, and the second touchelectrodes comprises a transparent conductive layer and an opaqueconductive layer disposed on the transparent conductive layer, whereinthe transparent conductive layer has a structure including at least onelayer formed of at least one of ITO, IZO, ZnO, and IGZO, and wherein theopaque conductive layer has a structure including at least one layerformed of at least one of Ti, Al, Mo, MoTi, Cu, and Ta.
 6. The displaydevice according to claim 4, wherein the opaque conductive layer of theupper routing line and the upper pad electrode is disposed on or beneaththe transparent conductive layer and has a same shape as the transparentconductive layer.
 7. The display device according to claim 4, whereinthe opaque conductive layer of the first and second touch electrodes andthe first bridge is provided on the transparent conductive layer and hasa line width smaller than that of the transparent conductive layer. 8.The display device according to claim 7, wherein the opaque conductivelayer of at least one of the first touch electrodes, the second touchelectrodes, the first bridge, and the second bridge has a mesh shape. 9.The display device according to claim 3, wherein at least one of thefirst bridge and the second bridge comprises at least one slit.
 10. Thedisplay device according to claim 1, further comprising a color filterdisposed between the encapsulation unit and the touch sensors.
 11. Adisplay device comprising: a light-emitting element disposed on asubstrate; an encapsulation unit disposed on the light-emitting element;a plurality of touch sensors disposed over the encapsulation unit; atouch insulation layer disposed on the encapsulation unit; a lowerrouting line disposed on the touch insulation layer having a pluralityof routing contact holes and covering a lateral surface of theencapsulation unit; and an upper routing line disposed on the touchinsulation layer along the lower routing line and connected to the lowerrouting line through the plurality of routing contact holes, wherein thelower routing line and the upper routing line are disposed on differentplanes and overlap each other.
 12. The display device according to claim11, wherein the plurality of touch sensors comprise: a touch drivingline having a plurality of first touch electrodes arranged in a firstdirection on the encapsulation unit and a first bridge interconnectingthe plurality of first touch electrodes disposed on the encapsulationunit so as to intersect each other, a touch sensing line having aplurality of second touch electrodes arranged in a second directionintersecting the first direction and a second bridge interconnecting thesecond touch electrodes, wherein one of the first and second bridges isformed of the same material as the lower routing line, and the upperrouting line extends from each of the first and second touch electrodes.13. The display device according to claim 12, further comprising a touchpad disposed on at least one of a plurality of insulation layersdisposed under the light-emitting element and extended from the upperand lower routing lines, wherein the touch pad includes a lower padelectrode extended from the lower routing line and an upper padelectrode extended from the upper routing line.
 14. The display deviceaccording to claim 13, wherein at least one of the upper routing line,the upper pad electrode, the first bridge, the first touch electrodes,and the second touch electrodes comprises a transparent conductive layerand an opaque conductive layer disposed on the transparent conductivelayer, wherein the transparent conductive layer has a structureincluding at least one layer formed of at least one of ITO, IZO, ZnO,and IGZO, and the opaque conductive layer has a structure including atleast one layer formed of at least one of Ti, Al, Mo, MoTi, Cu, and Ta.15. The display device according to claim 14, wherein the opaqueconductive layer of the upper routing line and the upper pad electrodeis disposed on or beneath the transparent conductive layer and has asame shape as the transparent conductive layer.
 16. The display deviceaccording to claim 14, wherein the opaque conductive layer of the firstand second touch electrodes and the first bridge is provided on thetransparent conductive layer and has a line width smaller than that ofthe transparent conductive layer.
 17. The display device according toclaim 16, wherein the opaque conductive layer of at least one of thefirst touch electrodes, the second touch electrodes, the first bridge,and the second bridge has a mesh shape.
 18. The display device accordingto claim 12, wherein at least one of the first bridge and the secondbridge comprises at least one slit.
 19. The display device according toclaim 11, further comprising a color filter disposed between theencapsulation unit and the touch sensors.
 20. A method of manufacturinga display device comprising: forming a light-emitting element on asubstrate; forming an encapsulation unit on the light-emitting element;forming a plurality of touch sensors above the encapsulation unit; andforming a plurality of routing lines connected to the plurality of touchsensors and covering a side surface of the encapsulation unit, whereinthe plurality of routing lines are disposed on different planes tooverlap each other and is electrically connected to each other through aplurality of routing contact holes.